1. CTA 09 - Introduction David Rubin Cornell Laboratory for
Accelerator-Based Sciences and Education

2. Objectives CesrTA Objective
Characterize the electron cloud phenomena in sufficient detail to
extend the predictive power of calculations and simulations so that
the limitations imposed by the electron cloud on the ILC damping ring
performance can be evaluated with confidence.
June 25, 2009
CTA 09 - Introduction

3. Status Extensive measurements of cloud buildup have been completed
- 22 RFAs are operating in wigglers, arc dipoles, drifts and
variable dipole field (chicane), copper, TiN, aluminum, SS
- Measurements in trains with 4ns, 8ns, 14ns spacing,
various bunch currents, 2GeV and 5GeV beam energy,
and scans of electron energy
- TE wave measurements through chicane and wigglers
- Bunch by bunch tune shift measurements vs energy,
bunch charge, bunch spacing - characterize global properties
of electron cloud
Additional RFA equipped chambers are being installed now
(Carbon alpha, grooved wiggler chamber, quadrupole chamber)
- Significant progress toward single bunch single pass measurement of
vertical beam size with x-ray beam size monitor
But have yet to measure sub 20pm vertical emittance and therefore we have
not yet characterized emittance diluting effect of the electron cloud
June 25, 2009
CTA 09 - Introduction

4. Objectives
Workshop objective is to define the remainder of the CesrTA program
- What experiments should be done at CesrTA and with what priority?
- When should the experiments be done?
- Who will be responsible for the measurements?
- Who will be responsible for the analysis?
- Is there additional instrumentation that should be developed? (again prioritize)
- Tests of mitigation techniques other than those already in the works
- What calculations, simulations, and modeling tools are required to enable
evaluation of the performance of the linear collider damping ring? (prioritize)
June 25, 2009
CTA 09 - Introduction

5. Workshop format 3 working groups
Electron cloud I (build up and mitigation)
K. Harkay, Y. Suetsugu, B. Zwaska
2. Electron cloud II
(e-cloud beam dynamics and simulation)
G. Dugan, J. Flanagan, J. Crittenden
3. Low emittance tuning
M. Billing, S. Guiducci, J. Shanks
June 25, 2009
CTA 09 - Introduction

6. Task list template To be completed by session conveners for closeout
June 25, 2009
CTA 09 - Introduction